A compound produced by gut bacteria from ellagitannins in pomegranate, walnuts and berries. Supplements supply it directly, because only a minority of people harbour the bacteria that make it.
Urolithin A is one of the better-argued products in the longevity category, and the argument turns on a genuinely interesting observation: eating pomegranate does not reliably deliver urolithin A, because producing it depends on gut bacteria that only around forty per cent of people carry. Supplying it directly removes that lottery. The human trials are real — randomised studies in middle-aged and older adults report improved muscle endurance and changes in mitochondrial gene expression markers — and they are also small, short and conducted by the company that developed and sells the compound. The muscle endurance findings have not yet been independently replicated, and the mitochondrial biomarker changes are surrogate endpoints rather than health outcomes.
Sold as
Capsule, Powder sachet, Combination with protein powders
Standardised to
Milligrams of urolithin A; the compound is synthesised rather than extracted, so purity is generally high — a product without this marker may not resemble what was studied.
Also known as
Mitopure, UA, Ellagitannin metabolite
Regulation: Sold as a dietary supplement in the US following a self-affirmed safety notification, with no pre-market efficacy review, and authorised as a novel food in the European Union with conditions. The great majority of the published clinical evidence comes from the company that sells it.
What the research used
The amounts, forms and durations published trials of Urolithin A actually administered.
These are the amounts published trials administered — not a recommendation, and not a dose to copy. Trial participants were screened, supervised and given a characterised preparation. What is in a retail bottle is frequently not what was studied, and the amount that suits one person is not general advice.
Studied for Muscle endurance in middle-aged adults
500–1000 mg
Limited
Capsule or powder, daily · 4 months
The dose in the main randomised trial, which reported improved muscle endurance. It was funded and conducted by the company selling the compound and has not been independently replicated.
Studied for Safety and mitochondrial biomarker studies
250–2000 mg
Limited
Single or repeated daily doses · 4 weeks
Dose-ranging studies in older adults measuring plasma acylcarnitines and muscle gene expression. These are surrogate markers rather than outcomes.
This is general information about food, not medical advice. It cannot diagnose, treat or replace guidance from a clinician who knows your history.
When it was taken
Each window says whether a trial compared it against an alternative, or whether it is convention and pharmacology. Most timing advice is the second kind.
None of the timings below were directly compared in a trial. They reflect how the research happened to dose, or what the pharmacology implies — which is not the same as a timing being better.
🍽️With food
Not enough
Taken with food in the trials for tolerability and absorption. No timing comparison has been published.
Timing was not directly compared. This reflects convention or how the compound behaves in the body, not a trial showing this window works better.
The evidence in depth
Best supported: Limited
What each association actually rests on, and the papers behind it. A rating describes the state of the research, not how promising the supplement sounds. How we rate evidence.
Randomised trials in middle-aged and older adults report improved muscle endurance and, in some measures, strength, after four months. The studies are small, short and conducted by the company that developed the compound, and independent replication has not yet appeared. A trial in trained athletes found no meaningful advantage, which suggests any effect depends on starting from a low baseline.
What may be going on: Urolithin A induces mitophagy, the selective clearance of damaged mitochondria, in laboratory and animal models, and human studies show changes in mitochondrial gene expression and plasma acylcarnitines.
Limited evidence. Early human work, or mostly lab and animal research.
Longevity framing derives from worm and mouse studies. No human study has measured any ageing outcome, and the human endpoints so far are muscle function and biomarkers.
Not enough evidence. Not enough human research to say anything useful yet.
Deep research mode adds each paper’s own conclusion and stated limitations.
Things to know
Interactions, contraindications and dose limits, most serious first. Concentrated extracts interact with medication in ways the whole plant does not, so this section carries more weight here than it does on a food page.
Worth knowing
Nearly all the evidence comes from one company
The clinical programme was designed, funded and published by the company that developed and sells urolithin A. The trials appear well conducted, and independent replication is still the thing that would establish the finding rather than support it.
Worth knowing
The effects are on surrogate and short-term measures
Improved muscle endurance over four months in previously sedentary adults is a modest and specific finding. Mitochondrial gene expression and acylcarnitine changes are biomarkers, and the leap from these to healthspan claims is entirely marketing.
Worth knowing
Long-term safety data are limited
Published human exposure runs to a few months. There is no long-term data, and no data in pregnancy, breastfeeding or childhood.
Worth knowing
Pomegranate juice is not equivalent
The point of the supplement is that most people do not convert pomegranate ellagitannins into urolithin A. Drinking pomegranate juice therefore does not reliably reproduce it — which is the honest version of the marketing claim and also its strongest argument.
In the food catalogue
The whole-food form, where one exists. The evidence for a concentrated extract rarely transfers to the food, or the other way round — these are cross-links, not equivalents.